Obsolete since JSAPI 42
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
Take care not to confuse the
JSVAL_FALSE with the
jsval values must not be used as C true/false values; there is no guarantee that the C bit-pattern of any particular
jsval is zero or nonzero.